<!DOCTYPE html>
<html>

<head>
    <!-- 背景测试 -->
    <meta charset="utf-8">
    <title>背景测试</title>


    <style>
        body{
            background-color: #496098;
            height: 100vh;
            margin: 0;
        }


        .bg {
            width: 500px;
            background-color: #EFF4FA;
            height: 100%;
            margin-left: auto;
            border-top-left-radius:  20% 50%;
            border-bottom-left-radius:  20% 50%;
        }
    </style>

</head>

<body>
    <div class="bg">
    </div>

</body>

</html>